The survival of a military unit depends to a great extent on its ability to defeat enemy armor and field fortifications. Substantial improvements in the effectiveness of armor and fortifications to withstand exploding munitions has occurred. Reinforced structures are generally designed to deflect the explosive force of a munition away from a target, or to absorb part of the destructive force as a way to dissipate the damaging effects of the munition. Munitions with a delayed warhead detonation, after target impact, have increased effectiveness in damaging or destroying the target.
The delayed timing of an exploding munition, after impact, may be required for several reasons. The purpose of the delay is to produce the greatest target effect or efficiency from the warhead. Some munitions penetrate the target without detonating and then function once inside. Other munitions utilize timing between multiple warheads to create the greatest effect against armor.
In addition to delayed timing, target discrimination is an important factor to produce the optimal penetration. Target discrimination has been under continuous development. One such development includes a bunker defeat munition (BDM), which is a shoulder-fired munition that is capable of discriminating between two targets. These targets are classified as either soft or hard, (i.e., sand or armor) to set a detonation delay time.
Reference is made to U.S. Pat. No. 8,091,478 that describes an exemplary BDM discrimination method, and which is incorporated herein by reference. The BDM discrimination algorithm samples the state of an acceleration switch during a target impact. Following a predetermined sample period, a circuit determines if the majority of samples were logic high or logic low and uses that determination to set an appropriate detonation delay time. The BDM algorithm uses a binary signal from the switch to decide between two outcomes or two target types.
Although this BDM technology has proven to be useful, it would be desirable to present additional improvements. In particular, it would be useful to autonomously discriminate between more than two discrete target media in order to increase munition effectiveness against a wide range of targets.
There is therefore a need for a target discriminating algorithm, which can be implemented into a munition, for use against military operations in urban terrain (MOUT) targets, including but not limited to earth and timber bunkers, triple brick walls, double reinforced concrete, and armored targets. The need for such a target discriminating algorithm has heretofore remained unsatisfied.